| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] a [num] [noun] period [prep] | 7 |
|
| 2 | [verb] a [num] [noun sg] period [prep] | 7 |
|
| 3 | [verb] a [num] [noun] period of | 5 |
|
| 4 | [verb] a [num] year period [prep] | 5 |
|
| 5 | [verb] a [num] [noun] period of | 5 |
|
| 6 | [verb] a [num] year period [prep] | 5 |
|
